This is a long story. My gf is on the bc pill, and has a history of irregular periods. She was on estrostep for 6 months, but she went off of it because it she only got her period once during that period. We and the doc weren't sure if the lack of period was because of the pill, or because of her tendency to irregularity. Anyway, after being off the estrostep for 1 month, she got her period exactly when expected. She immediately went on a new pill (per her doc), mircette, I think. She was on that for one month, and got her period exactly when expected, about four days ago. She only missed on pill - the rest she took on time, at the same time each day. The pill she missed wasn't an 'active' pill, and the instructions said we didn't need a backup method. My question is: We had sex on the second day of her period, and I came inside of her. Like I said, she'd been on the pill for a month, and the instructions said that we could have sex without a backup method after she'd been on the pill for 7days. The problem is, I've heard from friends and other websites that a girl should be on the pill for a least 1-2 months before sex without a backup. She is still having her period, two days later. Also, immediately after I came, she inserted spermicidal jelly. Should we be worried that she might be pregnant?

One month of use with a back-up. After that, the pill offers over 99% effectiveness against unplanned pregnancy (0% against STDs). Based on what you describe, you don't have much to worry about as far as a pregnancy.